Expansion means for self-contained liquid circulating systems



Feb. 5, 1963 3,076,479

K. OTTUNG EXPANSION MEANS FUR SELF-CONTAINED LIQUID CIRCULATING SYSTEMSFiled NOV- 2, 1960 United States Patent 3,076,479 EXPANSION MEANS FORSELF-CONTAINED LIQUID CIRCULATING SYSTEMS Kai Ottung, 8 Askebyvej,Virum, Denmark Filed Nov. 2, 1960, Ser. No. 66,827 1 Claim. (Cl. 138-30)The present invention relates to an expansion device for self-containedliquid circulating systems, particularly for use in the water coolingsystem of a motor vehicle.

Circulating systems, in which an expansion vessel is incorporated, arealready known, this vessel being either included in the actual path ofcirculation or connected thereto by a communicating pipe. The expansionof a liquid due to increase in temperature is accompanied simultaneouslyin such a system by a rise in pressure with the result that the materialof the components of the circulating system and of the associatedexpansion tank are subjected to not inconsiderable extra stress.

The present invention eliminates this drawback by including in thecirculating system, or in a chamber in communication therewith, areadily compressible container enclosing a space which is inaccessibleto liquid but which is in communication with the ambient air. In thisarrangement, on expansion of the liquid, the container can be compressedwithout any resistance so that expansion will not cause a rise in thepressure head, or raise it only to a slight amount depending uponwhatever slight resistance is offered by the container.

Should the liquid continue to expand after the container has beencompressed completely, then a considerable pressure rise will naturallyoccur.

In one embodiment of the invention this rise in pressure is controlledto a desirable extent by the inclusion in the circulating system, orinside the chamber, of a second, likewise compressible but closed,air-filled container. When the first container which communicates withthe outside atmosphere has been compressed completely, should furtherexpansion of the liquid occur, it will entail a considerable or slightamount of compression of the closed container so that the ensuingpressure rise will be uniform.

The location of one of the two compressible containers in a specialchamber is an advantage because any contaminating impurity carried intothe chamber by the expanding liquid will readily settle since the liquidin the chamber is relatively stagnant. Impurities can thus progressivelybe removed from the circulating system proper.

The invention is illustrated in the accompanying drawings in which:

FIGURES 1, 2 and 3 are sectional views showing an expansion device inaccordance with one embodiment of the invention and illustrating threestages in the expansion of the liquid in the system, and

FIGURE 4 is an alternative embodiment of the expansion device.

Referring to FIGURE 1 the expansion device comprises a chamber 1 havinga connection 2 to enable it to be connected to a circulating system (notshown) such as the water cooling system of a motor vehicle. In one wallof the chamber is a flanged vent pipe 3, by means of the flange 4 ofwhich a compressible container 5 in the form of a ball or bladder isfixed in position within chamber 1 so that the interior of said ball orbladder is cut oil i.e. inaccessibly to the liquid in the chamber 1 butis in direct communication with the ambient air. The chamber 1 alsocontains a second compressible container 6 which is completely closedand filled with a gas or air, for instance atmospheric air.

FIGURE 1 shows the expansion means as it appears when the liquid in thesystem is cold, whereas FIGURE 2 shows the manner in which on a rise intemperature of the liquid in the system the shape of container 5 iscaused to change, container 6 continuing to remain completely taut.

Any further rise in temperature causes expansion to continue until thecontainer 5 is completely compressed as shown in FIGURE 3. The manner inwhich the container 6 now begins to be compressed as the pressure in thesystem rises above the outside atmospheric pressure at more elevatedtemperatures can also be seen.

In the embodiment shown in FIGURE 4 the chamber 7 consists of rubber orsimilar material and is externally reinforced and stiffened by a rigidtube 8. At one end the chamber 7 is provided with a connection pipe 9:at its other end it is formed with an opening 10 to which a flexiblebellows 11 is fixed in such a way as to enclose the opening, the otherend of the bellows being sealed by an end plate 12. The bellows 11 issubdivided into two separate compartments 14 and 15 by a partition wall13, the operation and function of these chambers being the same as thatof the two containers 5 and 6 in FIG- URES 1 to 3.

The invention is particularly adapted for use in the water coolingsystems of internal combustion engines of motor vehicles and may behoused in the radiator.

I claim:

A thermal expansion compensating device for a closed cooling liquidcirculation system of an internal combustion engine, comprising, incombination, a first liquid displacing container surrounded at leastpartly by said cooling liquid, said container communicating with theatmosphere and having a flexible wall so as to be operative tocompensate for limited thermal expansion of said cooling liquid withoutsubstantial increase of the pressure thereof, and a second liquiddisplacing container surrounded at least partly by said cooling liquid,said second container being a closed gas filled container having aflexible wall so as to be compressible by the pressure of said liquidwhen the thermal expansion thereof exceeds said limited thermalexpansion.

References Cited in the file of this patent UNITED STATES PATENTS852,150 Whitney Apr. 30, 1907 2,132,952 Hewitt Oct. 11, 1938 2,497,020Singer Feb. 7, 1950 2,638,932 Alexander May 19, 1953

